Ostium 2, Black Moon Boogaloo

	The Thunder Kings, though not present at Isstvan, were present at a very early battle, the Assault on Ostium. The Emperor was enraged by the fracturing of the Terran Webway gate, but the thought of simply sending a force to execute his son was more than he could bear to think. The Voidwatcher would be brought back to Terra, so that his father could look him in the eye and hear the reasons for his treachery. For this purpose, the Emperor summoned his son Brennus and his Thunder Kings, who he knew would be uniquely suited to take on a legion of sorcerers. Brennus set out immediately with 60,000 Astartes, and a full demi-legion of Legio Canum titans. During the voyage, the Primarch and his Goffanoi worked nearly non-stop graving interlaced patterns of eldritch power on the arms and armor of the godlike war machines that would support them. The designs they carved were designed were designed to guard against warpcraft of all kinds. Brennus himself augmented the arms and armor of the Fera Judicii, an ancient Eclipse-pattern Warlord.

	During the time he spent working on the Titans, Brennus and his senior captains concocted a plan for the taking of the Voidwatcher's dark moon.